@Nanashi Anon Actually your three question marks are easy to fill in and you missed some options. Let me fix that for you.
First Empires: Scythian Women, Female commanders for Ancient China, warring states women, Hatshepsut in wargear, Pantea Arteshbod of Archimedean Persia, possibly Persian warrior women (bit of a stretch but the Archimedean Persians did have greater equality for women), Judge Debra if you really want to get Biblical.
Decline and Fall: Gladiatrix, since just got male gladiators.
Blood Oaths: Viking Shield Maidens and angry Irish girls (i.e. dark age farm girls fighting raiders).
Renaissance: Sengoku female "Home Guard" with naginata. Hussite militia. Female Pirates up through the Golden Age.
Napoleon's Wars: Militia, Spanish guerrillas, female combatants for the Polish revolution, Hollywood Female Pirates and female rioters for the mob.
Imperial Conquests: Frontier women ("Cowgirls", female bandits), Dahomeyan "Amazons", Samurai Women for the civil wars from that era, Victorian Adventuresses, Female Boxers, female combatants for the later European revolutions.
Great War: Woman's Battalion of Death.
World Ablaze: Female partisans (already done. Yes, but could make more with a Polish and/or Chinese focus), female Soviets (done by multiple makers already), Kokumin Giyuutai, Volksstrum (children so they look distinct from partisans? answer: nah, just add storm rifles and different hats and clothes)
General Accoutrements: Variety pack of heads. Maybe cavewomen too given the Neanderthals placement tag.
You can also add a “maybe Female steppe nomad X” to practically everything prior to WW1 and you might even be able to add them to Great War and World Ablaze too but not sure on interest there. I mean I added Scythian women already cause I know they are real, but you could probably add Xiongnu women to the First Empires list as well, similar deal with the Huns up to the Steppe nomads of 15th century, but they may even show up in Napoleon's Wars (know thier men folk did) and if the Turkish Bride manga has decent research backing it you could do some Turkish tribal ones and get away with it for the Great Game between Russia and the British Empire at least.
I am hoping they add “Female knights in plate armor” to fantasy, maybe female Barbarians or Adventurers, but I suppse even female orcs and goblins or ther monsters would be okay to good to.
Now that just covering things that should work with what is out there already in plastic, by themselves, and WA has plans for. Another good option would be the Trung Sister rebellion Vietnamese women (yes they had more female fighters in that war than just the Trung Sisters), the only issue is no Han Dynasty in plastic or planned for plastic so not alot of opponets.
Don't really know what they will add to Death Fields, but any of the above SciFied up would work plus several other options (ie figures to go with what they have already).